scholarly journals The Control of Plastid Pigment Formation by a Virescent Gene, Pale-Yellow-1, of maize.

1956 ◽  
Vol 31 (6) ◽  
pp. 415-420 ◽  
Author(s):  
Robert E. Kay ◽  
Bernard O. Phinney

In the previous communications of this series we have recorded the results of observations on the oxydases and chromogens concerned with the production of anthocyan pigments. The study of pigment formation is continued in the present communication, the sections of which deal with the following subjects :— 1. A pigment-producing glucoside of the wallflower ( Cheiranthus Cheiri ). 2. The formation of pigment-producing substances from glucosides. 3. The biochemistry of Mendelian colour characters Section 1.— A Pigment-producing Glucoside of the Wallflower. It is customary to divide the sap-pigments of plants into two series, the red, purple, and blue anthocyan pigments, and the yellow xanthein pigments. Miss Wheldale has, however, suggested, on genetical grounds, that the anthocyan and xantheiu pigments are related with one another. This author points out that most plants contain colourless or pale yellow substances which give a canary yellow colour with ammonia. When heated with dilute acid they assume a deep yellow colour and reduce Fehling’s solution. Hence, they are to be regarded as glucosides.


2020 ◽  
Vol 21 (24) ◽  
pp. 9769
Author(s):  
Saaya Koike ◽  
Kenshi Yamasaki

The epidermis is located in the outermost layer of the living body and is the place where external stimuli such as ultraviolet rays and microorganisms first come into contact. Melanocytes and melanin play a wide range of roles such as adsorption of metals, thermoregulation, and protection from foreign enemies by camouflage. Pigmentary disorders are observed in diseases associated with immunodeficiency such as Griscelli syndrome, indicating molecular sharing between immune systems and the machineries of pigment formation. Melanocytes express functional toll-like receptors (TLRs), and innate immune stimulation via TLRs affects melanin synthesis and melanosome transport to modulate skin pigmentation. TLR2 enhances melanogenetic gene expression to augment melanogenesis. In contrast, TLR3 increases melanosome transport to transfer to keratinocytes through Rab27A, the responsible molecule of Griscelli syndrome. TLR4 and TLR9 enhance tyrosinase expression and melanogenesis through p38 MAPK (mitogen-activated protein kinase) and NFκB signaling pathway, respectively. TLR7 suppresses microphthalmia-associated transcription factor (MITF), and MITF reduction leads to melanocyte apoptosis. Accumulating knowledge of the TLRs function of melanocytes has enlightened the link between melanogenesis and innate immune system.


Genetics ◽  
1991 ◽  
Vol 129 (4) ◽  
pp. 1099-1109 ◽  
Author(s):  
A G Reaume ◽  
D A Knecht ◽  
A Chovnick

Abstract The rosy gene in Drosophila melanogaster codes for the enzyme xanthine dehydrogenase (XDH). Mutants that have no enzyme activity are characterized by a brownish eye color phenotype reflecting a deficiency in the red eye pigment. Xanthine dehydrogenase is not synthesized in the eye, but rather is transported there. The present report describes the ultrastructural localization of XDH in the Drosophila eye. Three lines of evidence are presented demonstrating that XDH is sequestered within specific vacuoles, the type II pigment granules. Histochemical and antibody staining of frozen sections, as well as thin layer chromatography studies of several adult genotypes serve to examine some of the factors and genic interactions that may be involved in transport of XDH, and in eye pigment formation. While a specific function for XDH in the synthesis of the red, pteridine eye pigments remains unknown, these studies present evidence that: (1) the incorporation of XDH into the pigment granules requires specific interaction between a normal XDH molecule and one or more transport proteins; (2) the structural integrity of the pigment granule itself is dependent upon the presence of a normal balance of eye pigments, a notion advanced earlier.


1978 ◽  
Vol 176 (2) ◽  
pp. 359-364 ◽  
Author(s):  
Päivi Lehtovaara ◽  
Ulla Perttilä

The coupled oxidation of leghaemoglobins with O2 and ascorbate yielded oxyleghaemoglobin in the first reaction step, and the second step was the degradation of haem characterized by an A675 increase. Leghaemoglobins were degraded to biliverdin isomers specifically, depending on the structure of the protein. The main leghaemoglobin components of Glycine (soya bean) and Phaseolus (kidney bean) were degraded to biliverdin mixtures containing about 50% of the β-form, about 30% of the α-form and about 20% of the δ-isomer, whereas the leghaemoglobin I components of Vicia (broad bean) and Pisum (pea) were degraded almost exclusively to the β-isomer, with traces of the α-isomer. The amino acid sequences of Glycine and Phaseolus leghaemoglobins resemble each other, as do those of Vicia and Pisum. The site specificity of bile-pigment formation from leghaemoglobins can be tentatively explained by specific differences in the amino acid sequences at those regions of the polypeptide chain that are in the vicinity of the appropriate methine bridges. The ligand-binding site in different leghaemoglobins may be outlined on the basis of the present results, supposing that the haem is degraded when a reduction product of haem-bound O2 reacts with a methine bridge of the haem, and that the bridge specificity is regulated by hindering amino acid residues that determine the location of the bound O2. The residue phenylalanine-CD1 appears to be further away from the haem plane or in a markedly more flexible position in leghaemoglobins than in mammalian globins. The haem-bound oxygen atom B, in Fe–O(A)–O(B), seems to be free to rotate in all directions except that of the γ-bridge in Glycine and Phaseolus leghaemoglobins, but its position in Vicia and Pisum leghaemoglobin I might be restricted to the direction of the β-methine bridge.


Phytotaxa ◽  
2014 ◽  
Vol 164 (1) ◽  
pp. 17 ◽  
Author(s):  
Bao-Kai Cui ◽  
Chang-Lin Zhao

Phylogenies of Ceriporiopsis and related genera were studied using DNA sequences from the ITS+28S nuclear ribosomal RNA gene regions. Two species, Ceriporiopsis alboaurantia and C. semisupina, are described as new to science. Ceriporiopsis alboaurantia is characterized by annual growth habit, resupinate basidiocarps with white pore surface when fresh, turning to apricot-orange to dark orange upon drying, monomitic hyphal system with clamped generative hyphae encrusted with pale yellow crystals, ellipsoid and thin-walled basidiospores (4–5 ´ 3–3.3 µm), and plenty of pale-yellow to pale-orange oily substances in subiculum and trama. Ceriporiopsis semisupina is distinguished by annual, effused-reflexed basidiocarps with greyish brown to reddish brown pore surface, monomitic hyphal system with clamped generative hyphae bearing crystalline incrustation, long-clavate basidia, ellipsoid and thin-walled basidiospores (4–4.5 ´ 3–3.3 µm). Like previous study, the phylogenetic analysis presented here also showed that Ceriporiopsis is not monophyletic and the sampled species were grouped in four clades, including phlebia clade, residual polyporoid clade, tyromyces clade and gelatoporia clade.


1930 ◽  
Vol 62 (4) ◽  
pp. 84-87 ◽  
Author(s):  
M. C. van Duzee

Male: Length 2.6-3 mm. Head, thorax, abdomen, legs and feet thickly white pruinose, but the ground color showing through; face moderately wide, wholly pollinose, this pollen yellow in the middle, reaching the orbits at the suture, sides of upper part narrowly, below the suture widely white pollinose, sonsetimes the yellow pollen covers most of upper part and extends onto the inner part of the palpi; palpi with snow white pollen, each nearly as large as upper part of face; antennae wholly yellow, small, arista whitish; orbital cilia white, rather long on the sides; occiput, front, thorax and abdomen reddish coppery, posterior margins of abdominal segments sometimes green ; bristles of thorax small, black; hairs of ahdomen very short, white; pleura and coxae black with ground color nearly concealed with white pollen, tips of coxae yellow; hypopygium small, with a long, straight, black appendage extending forward under the abdomen and small yellowish appendages inside of this long one; femora, tibiae and tarsi pale yellow, last two joints of all tarsi blackish; the minute hairs on all femora and tibiae white, the small bristles on tibiae black; fore tibiae with a row of long white hairs on upper surface, which are as long as diameter of tibiae and extend to fourth tarsal joint, becoming shorter towards the end; apical joint of middle tarsi very slightly widened; pulvilli not enlarged ; joints of fore tarsi as 20-8-6-5-7 ; of middle ones as 32-14-9-6-6; joints of posterior pair as 25-19-11-6-7.


Phytotaxa ◽  
2021 ◽  
Vol 511 (2) ◽  
Author(s):  
ABDUL REHMAN NIAZI ◽  
MUHAMMAD ASIF ◽  
AIMAN IZHAR ◽  
ABDUL NASIR KHALID

During our surveys of fungi of some areas adjacent to the Cholistan desert, Punjab, Pakistan, we collected a new species in Lepiota sect. Echinatae. It was found on loamy soil under Vachellia nilotica and is described and illustrated as new based on the distinct morphology and ITS nrDNA analysis. The new species, Lepiota haroonabadensis, is characterized macroscopically by a light yellowish orange pileus covered with brown squarrose scales, bright yellowish to yellowish red stipe with pale yellow spiny scales, and rudimentary annulus; and microscopically by ellipsoid basidiospores, narrowly clavate to clavate cheilocystidia, cylindrical to sub-cylindrical or ellipsoidal elements of the pileus covering and cylindrical to globose elements of the stipe covering. A full description, color photos, line illustrations and a phylogenetic tree to show the position of the new species are provided.


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